Introduce IConnector for a unified way to handle initiating connections

Source/Client/MultiplayerStatic.cs

@@ -14,7 +14,6 @@
 using Multiplayer.Common;
 using RimWorld;
 using RimWorld.Planet;
-using Steamworks;
 using UnityEngine;
 using Verse;
 using Verse.Sound;
@@ -154,41 +153,30 @@ private static void SetUsername()
 
         private static void HandleRestartConnect()
         {
-            if (Multiplayer.restartConnect == null)
-                return;
+            var connString = Multiplayer.restartConnect;
+            if (connString == null) return;
 
-            // No colon means the connect string is a steam user id
-            if (!Multiplayer.restartConnect.Contains(':'))
+            if (!ConnectorRegistry.TryParse(connString, out var connector))
             {
-                if (ulong.TryParse(Multiplayer.restartConnect, out ulong steamUser))
-                    DoubleLongEvent(() => ClientUtil.TrySteamConnectWithWindow((CSteamID)steamUser, false), "MpConnecting");
-
+                Log.Error($"Failed to parse connection string from restartConnect: {connString}");
                 return;
             }
 
-            var split = Multiplayer.restartConnect.Split(new[]{':'}, StringSplitOptions.RemoveEmptyEntries);
-            if (split.Length == 2 && int.TryParse(split[1], out int port))
-                DoubleLongEvent(() => ClientUtil.TryConnectWithWindow(split[0], port, false), "MpConnecting");
+            DoubleLongEvent(() => ClientUtil.TryConnectWithWindow(connector, false), "MpConnecting");
         }
 
         private static void HandleCommandLine()
         {
             if (GenCommandLine.TryGetCommandLineArg("connect", out string addressPort) && Multiplayer.restartConnect == null)
             {
-                int port = MultiplayerServer.DefaultPort;
-
-                string address = null;
-                var split = addressPort.Split(':');
-
-                if (split.Length == 0)
-                    address = "127.0.0.1";
-                else if (split.Length >= 1)
-                    address = split[0];
-
-                if (split.Length == 2)
-                    int.TryParse(split[1], out port);
-
-                DoubleLongEvent(() => ClientUtil.TryConnectWithWindow(address, port, false), "Connecting");
+                if (LiteNetConnector.TryParse(addressPort, out var connector))
+                {
+                    DoubleLongEvent(() => ClientUtil.TryConnectWithWindow(connector, false), "Connecting");
+                }
+                else
+                {
+                    Log.Error($"Failed to parse connection string from command line: {addressPort}");
+                }
             }
 
             if (GenCommandLine.CommandLineArgPassed("arbiter"))

Source/Client/Networking/ClientUtil.cs

@@ -1,7 +1,5 @@
-using Multiplayer.Common;
-using Steamworks;
+using Multiplayer.Client.Util;
 using Verse;
-using Multiplayer.Client.Networking;
 
 namespace Multiplayer.Client
 {
@@ -12,36 +10,20 @@ public interface ITickableConnection
 
     public static class ClientUtil
     {
-        public static void TryConnectWithWindow(string address, int port, bool returnToServerBrowser = true)
+        public static void TryConnectWithWindow(IConnector connector, bool returnToServerBrowser = true)
         {
-            Find.WindowStack.Add(new ConnectingWindow(address, port) { returnToServerBrowser = returnToServerBrowser });
-
-            Multiplayer.session = new MultiplayerSession
-            {
-                address = address,
-                port = port
-            };
-
-            var conn = ClientLiteNetConnection.Connect(address, port);
+            var (conn, window) = connector.Connect();
             conn.username = Multiplayer.username;
-            Multiplayer.session.client = conn;
-            Multiplayer.session.ReapplyPrefs();
-        }
-
-        public static void TrySteamConnectWithWindow(CSteamID user, bool returnToServerBrowser = true)
-        {
-            Log.Message("Connecting through Steam");
 
             Multiplayer.session = new MultiplayerSession
             {
-                client = new SteamClientConn(user) { username = Multiplayer.username },
-                steamHost = user
+                client = conn,
+                connector = connector
             };
-
-            Find.WindowStack.Add(new SteamConnectingWindow(user) { returnToServerBrowser = returnToServerBrowser });
-
             Multiplayer.session.ReapplyPrefs();
-            Multiplayer.Client.ChangeState(ConnectionStateEnum.ClientSteam);
+
+            window.returnToServerBrowser = returnToServerBrowser;
+            Find.WindowStack.Add(window);
         }
     }
 }

Source/Client/Networking/JoinData.cs

@@ -290,9 +290,7 @@ public class RemoteData
 
         public IEnumerable<string> RemoteModIds => remoteMods.Select(m => m.packageId);
 
-        public string remoteAddress;
-        public int remotePort;
-        public CSteamID? remoteSteamHost;
+        public string connectionString;
 
         public ModListDiff CompareMods(List<ModMetaData> localMods)
         {

Source/Client/Networking/NetworkingSteam.cs

@@ -48,8 +48,13 @@ protected override void OnClose()
         public override string ToString() => $"SteamP2P ({remoteId}:{username})";
     }
 
-    public class SteamClientConn(CSteamID remoteId) : SteamBaseConn(remoteId, RandomChannelId(), 0), ITickableConnection
+    public class SteamClientConn : SteamBaseConn, ITickableConnection
     {
+        public SteamClientConn(CSteamID remoteId) : base(remoteId, RandomChannelId(), 0)
+        {
+            ChangeState(ConnectionStateEnum.ClientSteam);
+        }
+
         static ushort RandomChannelId() => (ushort)new Random().Next();
 
         public void Tick()

Source/Client/Networking/State/ClientJoiningState.cs

@@ -76,9 +76,7 @@ public void HandleJoinData(ServerJoinDataPacket packet)
             {
                 remoteRwVersion = packet.rwVersion,
                 remoteMpVersion = packet.mpVersion,
-                remoteAddress = Multiplayer.session.address,
-                remotePort = Multiplayer.session.port,
-                remoteSteamHost = Multiplayer.session.steamHost
+                connectionString = Multiplayer.session.connector.GetConnectionString()
             };
 
             var defDiff = false;

Source/Client/Networking/SteamIntegration.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using Multiplayer.Client.Networking;
+using Multiplayer.Client.Util;
 using Multiplayer.Client.Windows;
 using RimWorld;
 using Steamworks;
@@ -56,7 +57,7 @@ public static void InitCallbacks()
             {
                 if (Current.Game == null)
                 {
-                    ClientUtil.TrySteamConnectWithWindow(req.m_steamIDFriend, false);
+                    ClientUtil.TryConnectWithWindow(ConnectorRegistry.Steam(req.m_steamIDFriend), false);
                 }
                 else
                 {

Source/Client/Session/MultiplayerSession.cs

@@ -52,9 +52,7 @@ public class MultiplayerSession : IConnectionStatusListener
         public Process arbiter;
         public bool ArbiterPlaying => players.Any(p => p.type == PlayerType.Arbiter && p.status == PlayerStatus.Playing);
 
-        public string address;
-        public int port;
-        public CSteamID? steamHost;
+        public IConnector connector;
 
         public void Stop()
         {
@@ -102,11 +100,7 @@ public void NotifyChat()
         public void Reconnect(string username)
         {
             Multiplayer.username = username;
-
-            if (steamHost is { } host)
-                ClientUtil.TrySteamConnectWithWindow(host);
-            else
-                ClientUtil.TryConnectWithWindow(address, port);
+            ClientUtil.TryConnectWithWindow(connector);
         }
 
         public void Connected()

Source/Client/Util/ConnectorRegistry.cs

@@ -0,0 +1,102 @@
+using System;
+using System.Collections.Generic;
+using Multiplayer.Client.Networking;
+using Multiplayer.Common;
+using Steamworks;
+
+namespace Multiplayer.Client.Util;
+
+/// Contains all the data required to create a connection for the transport type (i.e., IP and port for LiteNetLib, and
+/// the host's steam id for Steam)
+public interface IConnector
+{
+    /// Does include the connector's prefix.
+    public string GetConnectionString();
+    public (ConnectionBase, BaseConnectingWindow) Connect();
+}
+
+/// Utility class for creating connectors and parsing them from a string based on their unique prefix.
+public static class ConnectorRegistry
+{
+    private delegate bool ConnStringParser(string connString, out IConnector connector);
+
+    private static readonly List<(string prefix, ConnStringParser parser)> ConnStringParsers =
+    [
+        (SteamConnector.Prefix, SteamConnector.TryParse),
+        (LiteNetConnector.Prefix, LiteNetConnector.TryParse)
+    ];
+
+    public static bool TryParse(string connString, out IConnector connector)
+    {
+        connector = null;
+        foreach (var (prefix, parser) in ConnStringParsers)
+        {
+            var prefixColon = $"{prefix}:";
+            if (connString.StartsWith(prefixColon)) return parser(connString.RemovePrefix(prefixColon), out connector);
+        }
+
+        return false;
+    }
+
+    public static IConnector Steam(CSteamID remoteId) => new SteamConnector(remoteId);
+    public static IConnector LiteNet(string addr, int port) => new LiteNetConnector(addr, port);
+}
+
+public class SteamConnector(CSteamID remoteId) : IConnector
+{
+    public static string Prefix => "steam";
+
+    /// Does not check if Prefix matches. Use ConnectorRegistry instead if that's desired.
+    public static bool TryParse(string connString, out IConnector connector)
+    {
+        if (ulong.TryParse(connString, out ulong steamUser))
+        {
+            connector = new SteamConnector((CSteamID)steamUser);
+            return true;
+        }
+
+        connector = null;
+        return false;
+    }
+
+    public string GetConnectionString() => $"{Prefix}:{remoteId}";
+
+    public (ConnectionBase, BaseConnectingWindow) Connect() =>
+        (new SteamClientConn(remoteId), new SteamConnectingWindow(remoteId));
+}
+
+public class LiteNetConnector(string address, int port) : IConnector
+{
+    public static string Prefix => "lnl";
+
+    /// Does not check if Prefix matches. Use ConnectorRegistry instead if that's desired.
+    public static bool TryParse(string connString, out IConnector connector)
+    {
+        var split = connString.Split(':', StringSplitOptions.RemoveEmptyEntries);
+        if (split.Length == 0)
+        {
+            connector = new LiteNetConnector("127.0.0.1", MultiplayerServer.DefaultPort);
+            return true;
+        }
+
+        if (split.Length == 1)
+        {
+            connector = new LiteNetConnector(split[0], MultiplayerServer.DefaultPort);
+            return true;
+        }
+
+        if (split.Length == 2 && int.TryParse(split[1], out int port))
+        {
+            connector = new LiteNetConnector(split[0], port);
+            return true;
+        }
+
+        connector = null;
+        return false;
+    }
+
+    public string GetConnectionString() => $"{Prefix}:{address}:{port}";
+
+    public (ConnectionBase, BaseConnectingWindow) Connect() =>
+        (ClientLiteNetConnection.Connect(address, port), new ConnectingWindow(address, port));
+}

Source/Client/Windows/JoinDataWindow.cs

@@ -759,12 +759,8 @@ private void DoRestart()
                     File.WriteAllText(Path.Combine(tempPath, $"{config.ModId}-{config.FileName}"), config.Contents);
             }
 
-            var connectTo = data.remoteSteamHost != null
-                ? $"{data.remoteSteamHost}"
-                : $"{data.remoteAddress}:{data.remotePort}";
-
             // The env variables will get inherited by the child process started in GenCommandLine.Restart
-            Environment.SetEnvironmentVariable(EarlyInit.RestartConnectVariable, connectTo);
+            Environment.SetEnvironmentVariable(EarlyInit.RestartConnectVariable, data.connectionString);
             Environment.SetEnvironmentVariable(EarlyInit.RestartConfigsVariable, applyConfigs ? "true" : "false");
 
             GenCommandLine.Restart();

Source/Client/Windows/ServerBrowser.cs

@@ -473,7 +473,7 @@ private void DrawSteam(Rect inRect)
                     if (Widgets.ButtonText(playButton, "MpJoinButton".Translate()))
                     {
                         Close(false);
-                        ClientUtil.TrySteamConnectWithWindow(friend.serverHost);
+                        ClientUtil.TryConnectWithWindow(ConnectorRegistry.Steam(friend.serverHost));
                     }
                 }
                 else
@@ -523,7 +523,7 @@ private static bool DirectConnect(string addr)
 
             try
             {
-                ClientUtil.TryConnectWithWindow(addr, port);
+                ClientUtil.TryConnectWithWindow(ConnectorRegistry.LiteNet(addr, port));
                 Multiplayer.settings.Write();
                 return true;
             }
@@ -570,7 +570,7 @@ private void DrawLan(Rect inRect)
 
                     var address = server.endpoint.Address.ToString();
                     var port = server.endpoint.Port;
-                    ClientUtil.TryConnectWithWindow(address, port);
+                    ClientUtil.TryConnectWithWindow(ConnectorRegistry.LiteNet(address, port));
                 }
 
                 y += entryRect.height;